Conditions that cause loss of bone mass and micro-architectural deterioration of bone structure affect many worldwide. For example, 44 million people age 50 or older are affected by osteoporosis in the United States alone. In addition, other conditions including, but not limited to, Paget's disease, osteolytic tumors, Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis, Osteoarthritis, osteopenia including drug induced osteopenia, and hypercalcemia also cause loss of bone mass and affect hundreds of millions of people worldwide.
These conditions predispose those suffering from these maladies to enhanced bone fragility and risk of fracture. Each condition has various etiologies such as congenital conditions, malnutrition, or various additional factors. For example, osteoporosis alone has at least three etiologies. The etiologies for osteoporosis have been established based on predisposing factors and clinical presentation, namely: postmenopausal (type I), senile (type II), and secondary (type III) osteoporosis. In all types, the declining ability of the bone remodeling machinery results in bone fragility. Type I postmenopausal osteoporosis (PMOP) occurs in women 51-75 years of age, in which, estrogen deficiency shifts bone remodeling to favor bone resorption over bone formation, which results in a net bone loss. Type II senile osteoporosis affects women at about twice the rate as men, and occurs from ages 75 to 90 years. Type III or secondary osteoporosis is caused by medications, cancers, endocrine disorders, chronic liver or kidney diseases, and additional conditions. The net result for each type of osteoporosis is the insidious loss of bone mass and the predisposition to traumatic bone fracture.
Numerous treatments have been administered to patients with these conditions; these treatments include the administration of hormone replacement therapy, antiresorptive agents, and immunosuppressants including monoclonal antibodies. However, administering therapeutic levels of these treatments often result in various side effects. For example, some treatments have been linked to various cancers, bone necrosis or osteonecrosis, and other unwanted side effects. Therefore, it is generally difficult to efficiently treat or prevent conditions that cause bone loss with the currently known compositions and methods.